The present invention relates to the institutional distribution of meals, for example in hospitals or other similar institutions, enabling foods placed on a meal tray to be stored and heated.
Institutional distribution of meals frequently uses meal trays on which foods are placed so that they are directly accessible to the person eating the meal without necessitating additional manipulations. The meal trays usually have a first tray portion carrying foods intended to be eaten cold, and a second tray portion carrying foods intended to be eaten hot. The meal trays are prepared in an institutional kitchen, then they are collectively transported in an insulated or refrigerated trolley that usually contains from 10 to 40 meal trays.
The above kind of trolley is described in U.S. Pat. No. 5,159,973, for example. The foods intended to be eaten cold are kept cold by an integral cooling device that operates on one half of each meal tray. The foods intended to be eaten hot are on the other half of each meal tray, which is insulated from the first half by a fixed partition. At meal times, personnel must remove the meal trays from the trolley and distribute them to the persons eating the meals.
One problem is complying with hygiene conditions, and especially temperature conditions, both for storing the foods and for heating them to the correct temperature. After heating, the foods intended to be eaten hot must be at a core temperature in the region of 65xc2x0 C., whereas the foods intended to be eaten cold must be at a core temperature of around 8xc2x0 C. But all of those foods are placed on the same meal tray, and it is clear that an exchange of heat tends to take place between the tray portion carrying the hot foods and the tray portion carrying the cold foods.
The above prior art devices do not comply with these hygiene conditions, and this encourages the growth of bacteria and the propagation of certain illnesses.
To improve the storage and heating of foods placed on a meal tray, enabling the foods to be kept cold until it is time to heat them, and to ensure correct heating, so that the foods are at a standardized temperature when the meals are eaten, a device for storing and heating foods placed on a meal tray has already been developed (see U.S. Pat. No. 6,120,819), the device comprising:
an insulated enclosure having an interior space for receiving a tray accessible via a front passage and divided into a rear compartment and a front compartment that communicate with each other via an intermediate passage,
a cooling device adapted to maintain an appropriate storage temperature in the interior space in the insulated enclosure for receiving a tray,
a heating device, adapted to generate a heat energy in a heating space in the front compartment or the rear compartment,
a front closure flap and an intermediate closure flap, that are mechanically coupled together using articulated arms to move vertically between (i) a closed position in which the front closure flap closes the front passage and the intermediate closure flap closes the intermediate passage above the meal tray to provide thermal insulation, and (ii) an open position in which the front closure flap and intermediate closure flap are retracted to allow the meal tray and the foods on it to move back and forth.
This kind of structure provides some thermal insulation between the portion containing the heated foods and the portion containing the cold foods, and in theory allows simultaneous manipulation of the thermal insulation flaps since the front flap is directly accessible to the user.
It has become apparent that the structure with two flaps described briefly in U.S. Pat. No. 6,120,819 is unsatisfactory: the vertical sliding movement of the two flaps requires sealed vertical lateral guide slideways and articulated connections to the connecting arms. These components complicate the fabrication of the device and increase its cost, necessitate special precautions to ensure a satisfactory seal, and most importantly constitute an assembly that is too complex to be easily cleaned and thereby comply with foodstuffs standards. The prior art document is silent on these problems and how they are possibly solved.
The problem addressed by the invention is that of designing a new thermal insulation structure between the hot and cold compartments that is, at the same time, simple, efficient and of low cost, and in particular allows easier cleaning in compliance with foodstuffs standards and hygiene conditions.
Another object of the invention is to design a device of the above kind that is particularly simple to manipulate, so it can be used by persons with reduced mobility, such as bedridden hospital patients.
To achieve the above and other objects, in a structure according to U.S. Pat. No. 6,120,819, the invention provides that the front closure flap and the intermediate closure flap are rigidly connected together by two longitudinal lateral arms that are mounted in the interior space for receiving a tray on two colinear transverse pivots, the two flaps and the two arms together forming a rigid assembly that tilts between an open position and a closed position. The device is simpler, in particular because the flaps no longer slide vertically in guide slideways, guidance being provided exclusively by the pivots.
The seal at the perimeter of the intermediate closure flap can be improved by providing simple elastic tongues, for example elastomer tongues, that bear and slide on a conformed contact surface. For example, the lateral edges of the flap are arcuate and centered on the rotation axis, and curved tongues fastened to the frame bear frontally on said lateral edges of the flap. The transverse edges of the flap are straight, and straight transverse tongues fastened to the frame bear frontally on said transverse edges of the flap.
It is advantageous to make the tilting rigid assembly easily demountable for cleaning by exploiting the elasticity of the tongues providing the seal. To this end, the pivots can be fixed horizontal pegs that engage vertically and removably in vertical notches in the bottom edges of the connecting arms. Alternatively, horizontal pegs can be provided on the connecting arms and removably engaged in vertical notches fixed with respect to the frame.
The heating space is preferably in the rear compartment, so that, the user can take hold of the cool area of the tray.
In one advantageous embodiment, the heating space is between a rear portion of the meal tray and a cloche that is placed over it to close said heating space. This improves the thermal insulation between the hot and cold food portions.
The device can advantageously include electrical power supply means adapted to supply electrical power to one or more electrical heating elements in the heating space.
The electrical heating element(s) are preferably incorporated into the wall of the cloche. This further improves the thermal insulation between the hot portion and the cold portion, preventing direct heat exchange via the body of the tray itself.
In one advantageous embodiment, the cloche is removable and is carried by the meal tray.
The device preferably further includes a complementary interior space, which is below the interior space for receiving the tray, accessible from an open front side, and cooled by the cooling device, and a front door for selectively closing off said open front side and the front passage in front of the front closure flap. A device of this kind can therefore serve simultaneously as a bedside table, a device for heating and storing foods on meal trays, and a refrigerator.